In recent years, rotating electrical machines such as electric motors and electric generators are required to have a small size, high output, and high efficiency. For size reduction and output increase of such a rotating electrical machine, a rotating electrical machine including a stator of concentrated winding having a relatively high coil space factor is used. However, there is an increased demand for a rotating electrical machine including a stator using a coil having a distributed winding structure that allows for further output increase (see, for example, Patent Document 1). Here, whereas a coil of concentrated winding is formed by winding a conductor wire on a single tooth, a coil of distributed winding is formed by winding a conductor wire between slots that are spaced apart from each other by two slots or more.